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Differential Pair Phase Tolerance DRC

Netsballer92

I tried to change a lot of things, but the DRC remains the same. I tried Phase Tuning and Delay Tuning. 

  • JuanCR
    0

    Hello,

    Can you please share a screenshot of how the routing of this Diff pair looks like? (start to end) According to what you're sharing, it looks like one branch is significantly longer than the other.

  • Netsballer92
    0 in reply to JuanCR

    Strange, cause I measured both traces and there is only a 3 mil difference. Must be some error in my OrCAD PCB layout software. Thank you. I'll try to reset the tolerance, maybe the error will go away. This software always has these little bugs.

  • steve
    0 in reply to Netsballer92

    Its unlikely to be a bug. Make sure Pinuse is setup correctly for the driver/receiver, also make sure you are running the latest hotfix (17.4-2019 S037, 22.1-2022 S004). Also make sure your diff pair is defined correctly (no xnets etc). All these can cause issues similar to what you are seeing.

  • avant
    0 in reply to steve

    I'll add to Steve's comment: In  electrical constraints / differential pair, select the diff pair, right click, and select analyze. 

    This will show the pin pairs of the two signals. It should be obvious if there is an error. I see this sometimes if there is a termination resistor on the nets.

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